Peanut weed control costs shaved

Paul L. Hollis Farm Press Editorial Staff | Feb 20, 2002

Looking at the typical peanut weed control program in the Southeast, there aren't many corners that can be cut or inputs that can be eliminated. There are, however, several things growers can do to become more cost-effective in controlling weeds.

Data from USDA shows that Georgia and Alabama peanut producers are spending an average of about $116 per acre on agricultural chemicals, says Eric Protsko, University of Georgia Extension weed scientist.

“That accounts for about 34 percent of the total operating costs of peanut producers. So, we're spending a good bit of money on chemicals, and on herbicides in particular. Most growers, however, won't be spending money on herbicides they don't need,” said Protsko at the recent Georgia Peanut Farm Show in Albany.

The typical peanut weed control program in the Southeast, he explains, include a preplant incorporated application of Sonalan, at about $5.66 per acre for two pints. This, he says, would be followed by an at-cracking application of Gramoxone Max and Storm, at about $15 per acre. Then, a producer might apply Cadre with a crop oil concentrate, at a cost of about $29 per acre. The total cost of this “typical” peanut weed control program is $50.29 per acre, he says.

“Can we be more cost effective by cutting out some of these inputs? No, not in the Southeast. We can't get rid of Sonalan because we have Texas panicum and Florida pusley. Some growers might not be spraying an at-cracking material. But research has shown that Cadre is more effective when it follows an at-cracking application of paraquat.

“We see quite a few farmers using a lower rate of Cadre. This will save you money in the short-term. But if you have a problem, the company isn't legally responsible to help you. Lower rates may work under certain situations, but they're not for every grower,” says Protsko.

While growers might not be able to eliminate inputs from their weed control programs, they can take steps to make their systems more cost effective, he says.

“We can't make any major cuts, but there are things we can do that together will help us to improve our bottom lines. Some of these things aren't major breakthroughs, but they are problems that I constantly encounter as I visit farmers throughout Georgia.”

One thing growers can do, says Protsko, is to read the herbicide label carefully. “Don't just look at the label. Look for things on the label that might help you to become more effective in controlling weeds. The label is one of the best resources available. Companies have spent $50 to $100 million developing a product, and a good portion of the information compiled during this development can be found on the label. The label will tell you about target weeds, recommended rates, timing and potential problems.”

Problems can be prevented, notes Protsko, by a more careful reading of the herbicide label. “Everybody is using paraquat on their peanuts. But you may not have seen some of the label statements that advise against spraying paraquat in dusty conditions.

“The label also might make a recommendation on the type of nozzle to use when spraying a herbicide. These recommendations will prevent problems and help you to become a more effective weed manager.”

Calibration of sprayers, says the weed scientist, probably is the most important thing growers can do to become more cost effective in managing weeds.

“Calibration is the only way to know if you're putting out the correct rate of a chemical. If you're not putting out enough, you'll have poor weed control, and you'll spend more money on another material. If the rate is too high, you're wasting money.”

Many of today's products, says Protsko, are low use-rate chemicals, with recommended rates in ounces or fractions of ounces. It's extremely important, he adds, that these chemicals are measured properly to prevent waste.

With the introduction in recent years of new postemergence herbicides for peanuts, some growers probably have considered leaving Sonalan or Prowl out of their weed control programs, he says.

“Whether we are using reduced or conventional-tillage, the yellow herbicides are the foundation of weed management in peanuts. They're very inexpensive when compared to other materials, about $4 to $5 per acre. They're essential for controlling Southeastern weed pests such as Texas panicum and Florida pusley. These materials must be incorporated by tillage or irrigation.”

Research has shown, adds, Protsko, that Sonalan and Prowl can be applied successfully through irrigation. “Some economists have said that it's $2 to $7 per acre cheaper to apply these materials with a center pivot than with a disk.”

In the past two years, several new soil-applied materials have been released, says Protsko, and growers should know when and where these materials will be useful.

“We need to use these materials on an ‘as needed’ basis, whenever, weed and rotation problems dictate. They can be expensive. And, in some cases, they need moisture to be effective. When we do use these materials, they may reduce the amount of postemergence materials needed.”

The timing of postemergence herbicide applications is extremely important in peanut weed control, says Protsko. “The timing of your postemergence applications is the most important thing you can think about when spraying herbicides. If you spray weeds when they're smaller, you'll get better control and better yields. If removed early in the life cycle, the weeds won't cause a yield loss.

“And, if the weed is smaller, you can lean towards a lower labeled rate. We don't need 100 percent weed control to harvest the best yields. Two inches or smaller is the ideal size for treating weeds, and you'll get the best results almost every time. If you wait until morningglories are running, you're wasting you're money with spraying. You may knock it back or slow it down, but it has already hurt yields, and you'll never get the control for which you paid.”

AN ESTIMATED 1,300 peanut producers attended the recent Georgia Peanut Farm Show in Albany. Growers were given the opportunity to see the products and check out the services of more than 70 exhibitors. University of Georgia Extension peanut specialists also presented their latest research findings during an educational session.